The transportation of large rectilinear articles, such as framed pictures or mirrors, requires special care and attention, since these articles are generally fragile. These articles are commonly set within a carton with their exterior edges spaced from the interior walls of the carton. Shock or impact absorbing materials are utilized in the space between the exterior edges of the article and the interior walls of the carton to cushion and protect the article from impact and damage during transportation and handling.
Inserts that are L-shaped have been utilized in the oorners of cartons to provide protection from impact. For instance, in U.S. Pat. No. 2,160,221, a protective corner pad is disclosed. The disclosed pad is constructed from sections of corrugated cardboard which are folded over each other. The size of the pad is, therefore, determined by the exterior dimension of the article to be transported, and is fixed during its construction by folding additional layers of cardboard. To modify the size of the pad when packaging the article, however, would require that a section of cardboard be scored in the appropriate locations and then the pad cut, folded and adjusted at the time of packaging, adding additional time, labor and expense to the packaging process.
In U.S. Pat. No. 3,302,782, a corner pad is disclosed the size of which is adjusted during the construction of the pad. This adjustment, therefore, requires prior knowledge of the specific dimensions of the article to be packaged and the disclosed corner pad in combined use with a container of specific size, can effectively be used to package articles of only a single size.
In U.S. Pat. No. 3,939,375, a special purpose carton is disclosed for shipping sheets or panes of glass which includes corner pads made of shock absorbing, compressible and resilient material, such as polyethylene. Shutting the top panels of the carton compresses the corner pads so as to support the glass sheets at their corners. The use of such corner pads is, however, limited by their size. A certain amount of compression of the interior faces of the pads by the edge of sheet of glass is required to adequately secure the glass pieces, so that if the space between the exterior edges of the glass pane and the interior of the carton is too large, either a smaller carton or larger corner pads must be obtained prior to packaging. Moreover, it is not clear that sufficient compressive forces could be applied to framed pictures and the like to deform the polyurethane material and thereby securely position the article away from the side walls of the outer carton during transportation and handling.